Add vim keybindings to code editor

[neov5]

Since #105 is WIP, could you consider a feature request to add vim keybindings? Add a toggle in the settings page to set the default keybindings for the editor, with the option to choose between vim/default keybindings, and enable vim keybindings using https://github.com/replit/codemirror-vim.

[redimp]

Hey @neov5, I agree having vim keybindings would improve the editing experience a lot (for people used to them).

I put this on my list, but please be patient its at the far end of my list, like #105.